Key operated switch



Oct. 3, 1933. M, GUETT 1,929,311

KEY OPERATED SWITCH Filed Jan. 3, 1931 A1 ON ON 6 Q 5% H O F2 or: 7 OFFO 345 70,

MONROE GUETT 2 2 aztarneys mm M Patented Oct. 3, 1933 UN ED STATES KEYOPERATED SWITCH Monroe Guett, Hartford, Conn assignor to The Arrow-Hart& Hegeman Electric Company, Hartford, Conn., a corporation ofConnecticut Application January 3, 1931. serial No. 506,456

4 Claims.

This invention relates to means for preventing unauthorized persons fromoperating electric switches. More particularly it relates to means forpreventing anyone from operating a keyi operated electric snap switch,with a screw driver, knife or other illegitimate operating device.

Heretofore key operated switches have been known and commonly used inmany places where it was desirable to prevent promiscuous operation ofelectric switches, but many of these switches could be operated by welldirected manipulation of screw drivers, bits of wire, nails, knives,etc.

It is an object of my invention to provide a .1 switch which is readilyoperable by a special key provided therefor, but which can not beoperated by any implements commonly employed to effect unauthorizedoperation of such switches.

Referring to the drawing: Fig. 1 is a plan view of a switch embodying myinvention. I

Fig. 2 is a side elevation section view of the invention, taken on line2-2 of Fig. 1.

Fig. 3 is an end elevation section view of the linvention taken on line33 of Fig. 2.

Fig. 4 is a bottom view of the housing employed in my invention toprotect the operating mechamsm.

Fig. 5 is a perspective view of the protecting Ihousing employed in myinvention.

Fig. 6 is a fragmentary detail view, in perspective, of the switchoperatinglever used in the embodiment of my invention shown in Figs.1-5.

In the drawing, the switch mechanism is supported from a conventionalswitch supporting strap 10 having a depressed central portion 12 towhich are secured depending legs 14 having V-notch bearings 16 cut intothem to support a conventional U-shaped switching member 18.

This switching member is adapted tobe thrown from one side of thebearing notches to the other by a tensioned spring 20 secured to theswitching member and to an operating lever 22 which is mounted foroscillation between thelegs 14 and pivotally supported by an axle 24passing through the ends of the legs 14. The operating lever isfiat andits upper portion projects through an aperture 26 in the strap 10,between the legs 14. A narrow curved plate 28 is secured to or may beformed integrally with the upper portion of the operating member 22. Theplate 28 is formed with an apertured ear 30 on each side of the plate,these ears being turned down from the plate toward the switch mechanismand the apertures 1131 are adapted to receive portions of a switchoperating key 32 as will be more fully explained hereinafter.

In order that the operating lever 22 and plate 28 may not be engaged andmoved by any implement other than the key 32 a protecting housing 34 ispositioned over the plate 28 and is held in that position by ametallichousing-positioning plate 36 which is secured on top of the supportingstrap 10 by screws 38 at each end of the plate,. these screws comingthrough the usual insulating base (not shown) for snap switches of thetype described.

The housing 34 (see Fig. 5) is made with a base portion 34a which iswider than the top portion 34b in order that the top portion may extend-9; through a suitable rectangular aperture in the plate 36 and that theplate 36 may rest on the shoulders 3&0 (see Fig. 2) between the upperand lower portions. The bottom of the lower portion of the housing ischannelled out to permit free oscillatory movement of the operatinglever 22 and plate 23; and the upper portion of the hous-' ing ishollowed out to permit reciprocatory movement of the key 32. An I-shapedslot is formed through the top surface of the housing through which thekey 32 may be inserted. Beneath this slot and centrally located in thehousing is a longitudinal guard rib 40 which prevents screw drivers,knife blades and the like from engaging the operating lever 22 and plate28 to operate the switch.

The key 32, for operating the switch, has a forked end which is adaptedto be inserted in the enlarged ends of the I-slot and to straddle therib 40. The tines of the fork are adapted to fit 6 into the apertures 31and engage with the ears 30 of the plate 28 to cause actuation of theoperating lever 22 by the key, as the key is moved from one end of theI-slot to the other.

From the foregoing the operation of my switch 9 5 will be readilyunderstood. Obviously the invention is not limited to the specific formof key and the specific embodiment of the invention I have shown. Manychanges and modifications within the scope of the invention will occurto those skilled in the art.

I claim:

1. In a key operated switch adapted to b placed behind a conventionalflush plate, switch operating mechanism movable in a plane perpendicularto the plane of the flush plate, protecting means for said switchmechanism having an opening into which an operating key may be insertedfor actuation of the switch, means beneath said, opening preventingdirect access to 1' 1 said operating mechanism and actuation thereof byillegitimate operating devices.

2. In a key operated switch, switch actuating mechanism, a protectinghousing 'for said mechanism having a longitudinal slot through which akey may be inserted to operate the switch, a longitudinal rib extendingbelow said slot and preventing direct engagement with and actuation ofsaid operating mechanism by illegitimate operating devices, said keybeing movable lengthwise of said slot to operate the switch between itsextreme positions.

3. In a key operated switch adapted to be placed behind a conventionalflush plate, switch operating mechanism movable in a plane perpendicularto the plane of the flush plate, a supporting strap for said mechanism,a protecting housing for reception of the switch operating key, and arib beneath the longitudinally extending portion "or the slot preventingaccess to and operation of said mechanismwby illegitimate operatingdevices.

MONROE GUETT.

